fix cross-compile on Darwin

package/gcc/patches/4.7.3/patch-libgcc_unwind-arm-common_inc

@@ -0,0 +1,14 @@
+--- gcc-4.7.3.orig/libgcc/unwind-arm-common.inc	2011-12-20 21:54:25.000000000 +0100
++++ gcc-4.7.3/libgcc/unwind-arm-common.inc	2014-02-05 15:10:25.000000000 +0100
+@@ -25,11 +25,6 @@
+ #include "tsystem.h"
+ #include "unwind.h"
+ 
+-/* Used for SystemTap unwinder probe.  */
+-#ifdef HAVE_SYS_SDT_H
+-#include <sys/sdt.h>
+-#endif
+-
+ /* We add a prototype for abort here to avoid creating a dependency on
+    target headers.  */
+ extern void abort (void);